Here's an example of what can happen if you keep the same metas for all page: here 344,000 pages indexed by google, but only index page displayed on site: command, and the rest shown as similar results. Wondering why more pages are not put in the supplemental list. Have anything to do with the PR 5 rank?? My directory's pages are more different than above site, but are in the supplementals.. (only PR4 - main site, PR0 for directory main page)
There's no real benefit in removing them. Some search engines do in fact still make use of them. But if what you're saying is true, then I might have to get a dynamic meta-tag generating script in place for my websites.